Do carbon spin poles etc need to be protected from the sun during boat storage? If so, is painting them a solution rather than making some kind of cover?

Yes, all carbon/epoxy parts need protection from UV. You can paint the parts, give them some layers of clear UV filtering finish or use a cover.

If you worry about your new Marstrøm parts, check with Sailcenter about an UV filter already applied.

Actually, the pole & snuffer on my Marstrom is from Guck Inc. in Rhode Island. I'll have to figure something out.

check out SystemThree WR-LPU two part polyurethane topcoat. clear gloss, thins with water, cleans up with soap and water, according to SystemThree it stops UV damage to your expoxy/carbon stuff.

Chesapeake Light Craft uses a couple of coats of varnish over their clear epoxy construction.

It depends on how they are made.
Pre preg have UV inhibitor in the resin.
Wet layup will usually need to be protected although I think West are now selling a hardener with UV inhibitor in it. Other manufacturers may also have this. Basically you need to find out what it was made from.

Let me get this strait. Carbon is affected by UV rays. Does that put the used boat buyer at risk in a few years?

My understanding is that it's not so much the carbon as it is the epoxy that holds it all together. Yes, if there is not a UV protector added then it will suffer frmo UV exposure.

Only if the carbon boat is unpainted or the spars are unpainted/varnised...Is this even an option?